The present disclosure relates to the field of improving ground, and more particularly to techniques for draining ground.
It is known to use drains, generally vertical drains, for consolidating and stabilizing ground that is soft and compressible, such as clayey ground. In particular, vertical drainage is generally used for accelerating the consolidation of relatively impermeable soft terrain supporting a heavy load, such as for example filling material. The presence of drains serves specifically to accelerate the removal of water from the ground, thereby enabling the ground to be consolidated in a few months. In contrast, in the absence of drainage, the consolidation or settling phenomenon can last for several years, which runs the risk of damaging the structure constructed on ground that has not been treated.
In order to drain ground, it is known to make use of machines for inserting drains in the form of elongate wicks vertically into the ground.
The disclosure relates to such a machine for putting a drain into place in ground, the machine comprising:                a drive tube presenting a longitudinal axis and having a bottom end;        a movement device for moving the drive tube in a direction parallel to the longitudinal axis;        a drain extending inside the drive tube and having a bottom end extending outside the drive tube;        at least one anchor;        a fastener device for fastening the anchor to the drain; and        a cutter member for cutting the drain and arranged under the fastener device.        
Such a machine is described in particular in FR 2 518 607.
In the method described in that document, the anchor is fastened in automatic manner to the drain, and then the drain together with the anchor are driven into the ground during the vertical descent of the drive tube. After reaching the desired depth, the drive tube is raised, leaving the drain in the ground because of the anchor that prevents the drain from rising.
In that document, the anchors are constituted by individual plates that are previously stored in a magazine. On each cycle, a plate is brought up to the drain in order to be stapled to the drain. That document also proposes another variant in which, instead of using a magazine of individual anchors, the anchors are detached from a strip scored with lines of weakness.
Nevertheless, that machine presents the drawback of being particularly expensive to fabricate since it requires individual anchors to be cut apart beforehand or else it requires prior machining of lines of weakness in a strip. Also, storing anchors in a magazine in the form of individual plates is generally not compatible with the working conditions encountered on a work site, such as vibration, sudden movements, or indeed the presence of mud.
Also, if the operator desires to change the size or the type of anchor, e.g. because of a local variation in the structure of the ground, it is necessary to act on the machine in order to reload the individual anchor magazine or else to replace the strip with a strip having lines of weakness in a different arrangement, thereby making it necessary to interrupt work on site in order to intervene on a machine so as to make such changes. Furthermore, there is a risk of accidents resulting from handling plates, since they are generally made of metal and are sharp.